eero on github

The Eero project uses GitHub for source control, issue tracking, and the technical documentation wiki.

• organization
• source code
• downloads
• wiki
• issues
• faq

what is eero?

Eero is a fully binary- and header-compatible dialect of Objective-C, implemented with a modified version of the Apple-sponsored LLVM/clang open-source compiler. It features a streamlined syntax, Python-like indentation, and other features that improve readability and code safety. It is inspired by languages such as Smalltalk, Python, and Ruby.

"Eero" is pronounced [ˈe-rō]‚ and is similar to the English word "aero".

code sample

(A compilable version with instructions can be found here.)

int main() 
  helper := FileHelper new  // declare variable "helper" via type inference
  files := []  // empty array literal implies mutable
  files addObject: (helper openFile: 'readme.txt')  // can group message in parens
  for FileHandle handle in files  // all objects are pointers, so no '*' needed
    Log('File descriptor is %@', (Number)(handle fileDescriptor)) // NSLog() call
    handle closeFile
  return 0  // semicolons are optional almost everywhere

interface FileHelper  // NSObject is implicit superclass when not specified
  // Similar properties can be grouped together
  property (readonly)
    String volumeName  // "String" is the same as "NSString"
    String volumeFormat
  // A class method. Methods are instance methods by default ('-' is optional).
  + pathStringWithComponents: Array, return String 
  // An instance method. The brackets make parameter "withPermissions" optional.
  openFile: String, [withPermissions: String], return FileHandle
end

implementation FileHelper  // no '@' needed for any objc keywords
  // "{}" braces are optional for instance variables
  private
    int iBytesUsed
    int iBytesFree
  // "components" is the default arg variable name for "pathStringWithComponents"
  + pathStringWithComponents: Array, return String
    fullPathName := ''  // empty objc string literal implies it is mutable
    for String component in components
      fullPathName << '/' + component  // string concatenation with '+' and '<<'
    return fullPathName
  // "withPermissions" was declared optional, so a default value is defined here
  openFile: String path, withPermissions: String = 'readonly', return FileHandle
    FileHandle handle = nil
    if permissions == 'readonly' or permissions == 'r'
      handle = FileHandle fileHandleForReadingAtPath: path
    else if permissions == 'readwrite' or permissions == 'rw'
      handle = FileHandle fileHandleForUpdatingAtPath: path
    return handle
end